Biological buffers with wide buffering ranges

ABSTRACT

Amines and amine derivatives that improve the buffering range, and/or reduce the chelation and other negative interactions of the buffer and the system to be buffered. The reaction of amines or polyamines with various molecules to form polyamines with differing pKa&#39;s will extend the buffering range, derivatives that result in polyamines that have the same pKa yields a greater buffering capacity. Derivatives that result in zwitterionic buffers improve yield by allowing a greater range of stability.

This application is a continuation in part of co-pending applicationSer. No. 12/751,053 filed Mar. 31, 2010 which was a continuation in partof application Ser. No. 12/606,762 filed Oct. 27, 2009 which was acontinuation in part of application Ser. No. 12/437,749 filed May 8,2009 which was a continuation in part of application Ser. No. 12/151,899filed May 9, 2008 which was a non-provisional of 61/124,586 filed Apr.17, 2008. Application Ser. No. 12/606,762 also claimed priority toprovisional 61/135,058 filed Jul. 16, 2009 and provisional 61/249,090filed Oct. 6, 2010. This application also claims priority to provisional61/249,090 filed Oct. 6, 2010.

BACKGROUND

1. Field of the Invention

The present invention relates generally to the field of amines and moreparticularly to a classes of amines used as buffers in biologicalsystems.

2. Description of the Problem Solved by the Invention

Amines are very useful compounds in the buffering of biological systems.Each class of amine has various limitations which require choosing anamine based on multiple factors to select the best amine. For example,pH buffering range is typically most important, but issues of chelation,and pH range stability, and solubility also come into play. Typically, asuboptimal buffer will result in yields that are well below thepotential yield. The invention disclosed improves the yields infermentation and purification, and improves shelf stability of proteinsand amino acids.

SUMMARY OF THE INVENTION

The present invention relates to amines and amine derivatives thatimprove the buffering range, and/or reduce the chelation and othernegative interactions of the buffer and the system to be buffered. Thereaction of amines or polyamines with various molecules to formpolyamines with differing pKa's will extend the buffering range,derivatives that result in polyamines that have the same pKa yields agreater buffering capacity. Derivatives that result in zwitterionicbuffers improve yield by allowing a greater range of stability.

DESCRIPTION OF THE FIGURES

Attention is now directed to the following figures that describeembodiments of the present invention:

FIG. 1 shows the derivation of polyamines and zwitterionic buffers fromtromethamine.

FIG. 2 shows the derivation of zwitterionic buffers and polyamines fromamino methylpropanol.

FIG. 3 shows the reaction of 2-methyl-2-nitro-1-propanol withacrylonitrile and its derivatives.

FIG. 4 shows the reaction of 2-nitro-2-ethyl-1,3-propanediol withacrylonitrile and its derivatives where x, y, and n are all integerswhere x and y are chosen independently, such that x+y=n and n is greaterthan zero.

FIG. 5 shows the reaction of 2-nitro-2-methyl-1,3-propanediol withacrylonitrile and its derivatives where x, y, and n are all integerswhere x and y are chosen independently, such that x+y=n and n is greaterthan zero.

FIG. 6 shows the reaction of tris(hydroxymethyl)nitromethane withacrylonitrile and its derivatives where x, y, z, and n are all integerswhere x, y and z are chosen independently, such that x+y+z=n and n isgreater than zero.

FIG. 7 shows the reaction of 2-nitro-1,3-propanediol with acrylonitrileand its derivatives where x, y, and n are all integers where x and y arechosen independently, such that x+y=n and n is greater than zero.

FIG. 8 shows the reaction of 2-nitro-1-butanol with acrylonitrile andits derivatives.

FIG. 9 shows FIG. 9 shows alkoxylation of aminomethylpropanol.

FIG. 10A shows the synthesis of a very mild, high foaming, surfactantderived from MCA.

FIG. 10B shows the synthesis of a very mild, high foaming, surfactantderived from SVS.

FIG. 11 shows the synthesis of a series of buffers with 2-nitropropaneas the starting material.

FIG. 12 shows FIG. 12 shows the synthesis of a series of buffers with1-nitropropane as a starting material where n and m are integers wherem+n is greater than zero and n is greater than or equal to m.

FIG. 13 shows the synthesis of a series of buffers with nitroethane as astarting material where n and m are integers where m+n is greater thanzero and n is greater than or equal to m.

FIG. 14 shows the synthesis of a series of buffers with nitromethane asa starting material where x, y, z and n are integers and x+y+z=n and nis greater than zero.

FIG. 15 shows the synthesis of a series of zwitterionic buffers based onacrylic acids.

FIG. 16 shows the synthesis of a zwitterionic sulfonate based ontromethamine.

FIG. 17 shows the synthesis of a zwitterionic sulfonate based on aminomethylpropanol.

FIG. 18-25 show the synthesis of families of zwitterionic buffers fromnitroalcohols.

FIG. 26 shows the synthesis of zwitterionic buffers from morpholine.

FIG. 27 shows the synthesis of zwitterionic buffers from hydroxyethylpiperazine.

FIG. 28 shows the synthesis of zwitterionic buffers from piperazine.

FIG. 29 shows the synthesis of zwitterionic buffers from ethyleneamines.

FIG. 30 shows the synthesis of a zwitterionic buffer with primary,secondary, tertiary, or quaternary amine functionality.

FIGS. 31-33 show the synthesis of mild zwitterionic surfactants fromnitroalcohols.

FIG. 34-37 show the synthesis of polyamines from nitroalcohols.

FIG. 38 shows the synthesis of diamines from nitroalcohols andaminoalcohols.

FIG. 39 shows the synthesis of isopropyl amine acrylate buffers and mildsurfactants.

FIG. 40 shows the synthesis of zwitterionic buffers from SVS and MCAderived from isopropyl amine as well as mild surfactants and diamines.

FIG. 41 shows the synthesis of a sultaine zwitterionic buffer ofisopropyl amine.

FIG. 42 shows the synthesis of zwitterionic buffers from amino alcoholsand itaconic acid.

FIG. 43 shows the synthesis of nitro acids from nitroalcohols anditaconic acid.

FIG. 44 shows the synthesis of primary amino zwitterionic buffers fromnitro acids.

FIG. 45. shows the synthesis of a family of zwitterionic buffers fromitaconic acid and amines.

FIG. 46 shows the synthesis of surfactants from amines and itaconic acidintermediates.

FIG. 47 shows the synthesis of nitroacids from nitroparaffins anditaconic acid.

FIG. 48 shows the synthesis of zwitterionic buffers from nitro acids.

FIG. 49 shows the synthesis of zwitterionic buffers from4-aminopyridine.

FIG. 50 shows the synthesis zwitterionic buffers from the ketimineconformation of 4-aminopyridine.

FIG. 51 shows the synthesis of zwitterionic sultaines from4-aminopyridine.

FIG. 52 shows the synthesis of zwitterionic buffers from taurine.

FIG. 53 shows the synthesis of zwitterionic buffers from homotaurine.

FIG. 54 shows the synthesis of zwitterionic buffers from aspartic acid.

FIG. 55 shows the synthesis of sultaine zwitterionic buffers from sodiumbisulfite and epichlorohydrin.

FIG. 56 shows the synthesis of sultaine zwitterionic buffers from sodiumbisulfite, epichlorohydrin, and aminoalcohols.

FIG. 57 shows the synthesis of zwitterionic buffers from propane sultone

Several drawings and illustrations have been presented to aid inunderstanding the invention. The scope of the present invention is notlimited to what is shown in the figures.

DETAILED DESCRIPTION OF THE INVENTION

Combining amines with monochloroacetic acid (MCA) or sodium vinylsulfonate (SVS) results in products are zwitterionic buffers that canbuffer in both acidic and basic pH conditions. A limited number aminesare currently used for this purpose, such as, tromethamine and ammonia.The reaction of amines, alcohols, and aminoalcohols with acrylonitrile(via the Michaels Addition), followed by reduction results in amines andpolyamines that have a broad buffering range. The further derivatizationof the amines and polyamines with MCA and SVS yields a further crop ofamine buffers with desirable properties. One skilled in the art willrecognize that MCA and sodium monochloroacetic acid (SMCA) can be usedinterchangeably.

The reaction of tromethamine as described above yields the products inFIG. 1. In step 1 in FIG. 1 where the acrylonitrile is added to theamine a branched structure wherein the addition of acrylonitrile resultsin a tertiary amine is shown. In reality, particularly when n is greaterthan 1, a mixture of products is obtained that is both tertiary andsecondary. For the invention disclosed herein, n may equal any integergreater than zero, including 1. Controlling the reaction temperature,pressure and agitation will allow the mixture to be predominatelysecondary (such as when m=n) or tertiary amine, m can be any integerless than or equal n. Furthermore, this selection can take place inadding acrylonitrile to the amine that results, allowing a progressivelymore branched product. It is within the scope of the invention disclosedherein to include these additional types of products and theirsubsequent derivatives described herein.

With regard to the reaction of the polyamine resulting from the secondstep in FIG. 1. FIG. 1 shows the addition of only one mole of SVS orMCA, it is known in the art, that a second mole may be added to obtain aproduct with a second zwitterionic group. Furthermore, in the case wherethe product has repeated additions of acrylonitrile and reduction to theamines, the branched products may have many more zwitterionic groups.Also, it is to be noted that, while the sulfonates are shown as sodiumsalts, other salts and the free acids (non-salted form) are also withinthe scope of this invention.

Other amines that would make excellent starting materials in place oftromethamine are 2-amino-2-methyl-1-propanol, 2-amino-1-butanol,2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, anddihydroxymethylaminomethane.

Additionally, fatty amines, such as lauryl amine, coco amine, tallowamine, and oleoyl amine, and fatty ether amines, such asbis-(2-hydroxyethyl) isodecyloxypropylamine, when reacted with SVSproduce mild surfactants that find utility where zwitterionicsurfactants are desired, including personal care.

Other amines that are shown in FIG. 2 are produced via a similar seriesof reactions, except that FIG. 2 includes zwitterionic buffers from theamine 2-amino-2-methyl-1-propanol, as well as the polyamines derivedfrom the reaction with acrylonitrile and the subsequent derivativesdescribed above. Other amines can be utilized in addition to2-amino-2-methyl-1-propanol to obtain excellent buffers are2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol,2-amino-2-methyl-1,3-propanediol, and dihydroxymethylaminomethane.Reaction conditions could be created such that the alcohol groups on theamines listed above could be reacted with acrylonitrile as well, andthen reduced to the amines and, if desired, reacted with SVS or MCA toimpart zwitterionic character.

Polyamines with good properties for use in biological fermentations,purifications, storage and general handling can also be produced throughthe reaction of nitroalcohols and acrylonitrile, followed by reduction.Additional derivatization with SVS or MCA will result in zwitterionicbuffers with a very large buffering range and capacity.

FIG. 3 shows the reaction of 2-methyl-2-nitro-1-propanol withacrylonitrile and its derivatives.

FIG. 4 shows the reaction of 2-nitro-2-ethyl-1,3-propanediol withacrylonitrile and its derivatives where x, y, and n are all integerswhere x and y are chosen independently, such that x+y=n and n is greaterthan zero.

FIG. 5 shows the reaction of 2-nitro-2-methyl-1,3-propanediol withacrylonitrile and its derivatives where x, y, and n are all integerswhere x and y are chosen independently, such that x+y=n and n is greaterthan zero.

FIG. 6 shows the reaction of tris(hydroxymethyl)nitromethane withacrylonitrile and its derivatives where x, y, z, and n are all integerswhere x, y and z are chosen independently, such that x+y+z=n and n isgreater than zero.

FIG. 7 shows the reaction of 2-nitro-1,3-propanediol with acrylonitrileand its derivatives where x, y, and n are all integers where x and y arechosen independently, such that x+y=n and n is greater than zero.

FIG. 8 shows the reaction of 2-nitro-1-butanol with acrylonitrile andits derivatives.

FIGS. 2 through 8 are subject to the same clarifications as FIG. 1 withregard to the cyanoethylation and the formation of a more linear orbranched structure as well as the addition of SVS or MCA in molarequivalents of primary amine groups or less than molar equivalents ofprimary amine groups present.

The buffers described thus far may also be ethoxylated, propoxylated, orbutoxylated to modify their properties. Ethoxylation will tend to impartsurfactancy to the resulting product. Propoxylation will addsurfactancy, but also reduce the water solubility. This is useful inemulsion breaking and reverse emulsion breaking, this will also findutility in breaking up and dissolving biofilms. This is also desired inoil-field applications. Butoxylation will similarly shift the HLB to thehydrophobic. Combinations of ethoxylation, propoxylation, andbutoxylation can be tailored to specific emulsion and reverse emulsionforming and breaking requirements. FIG. 9 shows alkoxylation ofaminomethylpropanol. The direct 2 mole ethoxylation of2-amino-2-methyl-1-propanol with 2 moles of ethylene oxide, as shown inFIG. 9 produces an excellent biological buffer with less chelation than2-amino-2-methyl-1-propanol. The reaction of 2-amino-2-methyl-1-propanolwith propylene oxide or butylene oxide yields a similarly less chelatingproduct, as does the reaction with diethylene glycol. The reactionproduct of 2-amino-2-methyl-1-propanol with 1 mole of diethylene glycolas shown in FIG. 9 produces an ideal amine for gas scrubbing of H₂S.This product is particularly useful because it does not bind to carbondioxide and carbon monoxide in any appreciable amount. Thus making itideal for tail gas scrubbing and maximizing the capacity of sulfurplants in refineries. Similar performance is seen with the reaction ofthe following amines 2-amino-1-butanol,2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol,tris(hydroxylmethyl)aminomethane, and 2-amino-1,3-propanediol.

The buffers described herein also make excellent starting materials forsurfactants. FIG. 10 shows the synthesis of 2 very mild, high foaming,surfactants that are well suited for personal care applications wereirritation is problematic, such as baby shampoo and face cleansers.Similar results are seen when 2-amino-1-butanol,2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol,tris(hydroxylmethyl)aminomethane, and 2-amino-1,3-propanediol are usedas the starting material in place of 2-amino-2-methyl-1-propanol.

Polyamines with good properties for use in biological fermentations,purifications, storage and general handling can also be produced throughthe reaction of nitroalkanes and acrylonitrile, followed by reduction.Additional derivatization with SVS or MCA will result in zwitterionicbuffers with a very large buffering range and capacity. FIG. 11 showsthe synthesis of a series of buffers with 2-nitropropane as the startingmaterial. FIG. 12 shows the synthesis of a series of buffers with1-nitropropane as a starting material where n and m are integers wherem+n is greater than zero and n is greater than or equal to m. Branchingcan be imparted on the buffers described in FIGS. 11 through 14 for thepolyamines that have greater than 3 amine groups by reducing theresulting nitrile or polynitrile to the polyamine and then reacting withmore acrylonitrile and then reducing the resulting nitrile groups toamine groups. This can be done repeatedly. As in FIG. 1, conditions canbe chosen such that a more branched product results. A more linearproduct is produced by simply adding all the acrylonitrile in one step,and then reducing the resulting polynitrile to the polyamine. For FIGS.12 through 14, the zwitterionic products can be made by adding MCA orSVS as shown in FIGS. 2 through 8.

FIG. 13 shows the synthesis of a series of buffers with nitroethane as astarting material where n and m are integers where m+n is greater thanzero and n is greater than or equal to m. FIG. 14 shows the synthesis ofa series of buffers with nitromethane as a starting material where x, y,z and n are integers and x+y+z=n and n is greater than zero.

Several descriptions and illustrations have been presented to enhanceunderstanding of the present invention. One skilled in the art will knowthat numerous changes and variations are possible without departing fromthe spirit of the invention. Each of these changes and variations arewithin the scope of the present invention.

Another embodiment of the present invention is the synthesis ofzwitterionic buffers with vinyl acids. FIG. 15 shows the synthesis of afamily of zwitterionic buffers based on members of the acrylic acidfamily. However, other vinyl acids may be used. Vinyl acids such asacrylic, 3-butenoic acid, 4-pentenoic acid, and other carboxcylic acidswith a double bond at the terminus. Carboxcylic acids with a triple bondat the terminus also can be utilized, similarly, an acid where themultiple bond is not at the terminus, such as hex-4-enoic acid, can alsobe utilized. However, due to the reduced commercial availability of suchcompounds, the preferred embodiment is the vinyl acid with a double bondat the terminus. One very large benefit of utilizing vinyl acids to makezwitterionic buffers is that the product does not need to be ionexchanged to produce a non-ionized form. In the market, both ionized, orsometimes called salted, and non-ionized forms sometimes called freeacid or free base, are required. In situations where ionic strength mustbe very closely controlled, the non-ionized forms are more popular. Forcases where increased water solubility and ease of solution are desired,the salted forms are preferred. It is understood to one skilled in theart, the present invention covers both the ionized and non-ionized formsof the buffers disclosed herein.

Another embodiment of the present invention is the sulfonatezwitterionic buffers derived from the reaction of an amine with anepichlorohydrin and sodium bisulfate condensate as described in FIG. 16.It is understood by one skilled in the art that other sulfate salts canbe utilized to arrive at the desired molecular structure and is includedin the present invention. FIGS. 17 through 25 teach the flexibility ofthe present invention to synthesize a series of a amine sulfonate oramino acid zwitterionic buffers from nitroalcohols or alkanolamines toproduce zwitterionic buffers that have primary amino functionality orsecondary amino functionality. In cases where there are more than onereactive group, amine, alcohol, or a combination, multiple sulfonategroups or acid groups can be reacted by adding more than one equivalentof the vinyl acid or the oxirane containing sulfonate.

Another embodiment of the current invention is to make zwitterionicbuffers with cylcoamines as the starting material. The cycloaminesresult in a tertiary amino group that is less chelating and interferesless in biological functions. FIG. 26 shows the reaction of morpholinewith a vinyl acid and morpholine with the oxirane sulfonate. FIG. 27teaches similar products, but utilizing hydroxyethyl piperazine. FIG. 28teaches the use of diamines as starting materials by using piperazine asthe starting material. This is a good example of a synthesis ofpolyzwittterionic buffers as discussed earlier. FIG. 29 teaches the useof ethylene amines to make zwitterionic buffers through reaction withvinyl acids or oxirane sulfonates. One skilled in the art will recognizethat similar compounds can be made by using ethylene amines, such asmonoethanolamine and the higher homologs, such as diethylenetriamine andis part of the invention disclosed herein.

Another embodiment of the current invention is the synthesis ofzwitterionic amines that have primary, secondary, tertiary, andquaternary amine functionality. FIG. 30 teaches this via oxiranesulfonate and amines. It is obvious to one in the art that any primary,secondary, or tertiary amine can be used in place of the methyamines inFIG. 30. While not shown in the figure, it is obvious to one skilled inthe art that the resulting amines can be reacted further with vinylacids, monochloroacetic acid, sodium vinyl sulfonate, or an oxiranesulfonate to further add acidic character to the zwitterionic buffer.

Another embodiment of the current invention is the synthesis of mildsurfactants from nitroalcohols. FIGS. 31 through 33 teach the synthesisof these mild surfactants. Lower molecular weight acids produce lowerfoaming mild surfactants, whereas higher molecular weight carboxcylicacids yield higher foam. Lauric acid is the preferred embodiment for ahigh foaming, mild surface. Coconut fatty acid performs similarly, butat a lower cost. A good surfactant with low foam can be made usingoctanoic acid as the carboxcylic acid.

Another embodiment of the current invention is the synthesis ofpolyamines from nitroalcohols. FIGS. 34 and 35 teach the synthesis ofdiamines from nitroalcohols. FIG. 34 teaches the synthesis with severalhydroxyl groups present. It is understood by one skilled in the art thatadditional amino groups can be added by reacting more than oneequivalent of epichlorohydrin to the nitroalcohol, up to the number ofhydroxyl groups, and then reacting the same number of equivalents ofamine to the oxirane containing amine. In the case where thenitroalcohol is reduced to the amino alcohol in the beginning, theaddition of base, such as caustic, to the amino alcohol will assist inthe reaction of the epichlorohydrin with the hydroxyl groups. Withoutthe base, the epichlorohydrin will preferably react with the amine asoutlined in the 1 equivalent addition depicted in FIG. 34 and FIG. 35.FIG. 26 demonstrates that tertiary amines can be used to makezwitterionic buffers with quaternary amine functionality from tertiaryamines. While not explicitly shown, any other tertiary amine can be usedas the starting material and is part of the invention described herein.FIG. 37 and FIG. 38 demonstrate that diamines can be made fromnitroalcohols by reacting sequentially the nitroalcohol withepichlorohydrin and then the second equivalent of the nitroalcohol,followed by reduction. Also taught is that a reduction step can takeplace in the beginning to yield a diamine with two secondary aminogroups. It is understood by one skilled in the art that thenitroalcohols or alkanolamines do not need to be symmetric, but othersmay be used in the synthesis of the diamine and is part of the inventiondisclosed herein.

FIG. 42 teaches the synthesis of zwitterionic biological buffers fromamino alcohols and itaconic acid. These buffers have two acid groups andincreased buffering in the acidic range of pH 3-6. FIGS. 43 and 44 showthe synthesis of zwitterionic buffers with primary amine groups. Thesebuffers are preferred in applications such as personal care wheresecondary amines are seen as undesirable. The nitro diacids of FIG. 44also have great utility as chemical intermediates when synthesizingbioactive molecules.

FIG. 45 teaches the synthesis of a family of zwitterionic buffers fromitaconic acid. The buffers in FIG. 45 are not limited to amino alcoholsas starting materials and provide a wide range of molecular size andsolubilities.

FIG. 46 teaches the synthesis of a family of amphoteric surfactants.These surfactants are preferred for there mildness, ability to performin hard water conditions and persistent lather when in the fatty tail isapproximately 10-12 carbons in length. The R group in FIG. 46 is toencompass the fatty acid family of carbon chain lengths, generally fromabout 6 to about 22 carbons. In the specific cases illustrated of lauricamine and lauric dimethyl amine reacted with itaconic acid, it isunderstood by one in the art that any chain length amine can be used andis in within the scope of the invention herein. Particularly, but notlimited to the fatty amines (carbon lengths of about 6 to about 22carbons, branched and linear, saturated and unsaturated), isopropylamine and butyl amine. The lower carbon chain lengths produce lowfoaming hard surface cleaners, while the carbon chains of about 8 to 10tend to produce the most foam. Higher chain lengths find utility asmineral collectors in floatation processes such as those employed iniron and potash mining.

FIG. 47 shows the synthesis of nitro acids from nitroparaffins. Asstated early, these are very flexible intermediates, particularly whensynthesizing bioactive molecules. Reduction of the nitro acids, as shownin FIG. 48 produces zwitterionic buffers with primary amine character.In the case of nitroparaffins that have more than one hydrogen bound tothe nitro bound carbon, more than one addition of the itaconic acid canoccur. The substitution can occur up to the number of hydrogen atomsbound to the nitro bound carbon.

FIG. 49 shows the synthesis of zwitterionic buffers from4-aminopyridine, FIG. 50 shows using the less stable ketimineconformation as the starting material. FIG. 51 shows the synthesis ofsultaine type buffers from 4-aminopyridine. Additional buffers can bemade by propoxylating and butoxylating 4-aminopyridine. The ethoxylatingand propoxylating will reduce the water solubility and reduce thebioavailability. This is one method of extending the time a material isbioavailable by making it available slowly, particularly if the moleculeis metabolized. Additionally, a triamine can be made by reacting2-aminopyridine with acrylonitrile and reducing it to the triamine, orreacting with allylamine to keep the aromatic nature of the six memberedring. The resulting buffers are excellent buffers in their own right,but also have great promise in treatment of multiple sclerosis, andother conditions that can benefit from calcium or other cationinhibition. The anionic components, in particular, are all groups thatcan chelate cations.

FIG. 52 outlines the synthesis of taurine derived zwitterionic buffers.These molecules, along with the products in FIG. 53, homotaurine derivedzwitterionic buffers, are expected to find great utility in thepurification of proteins and in cell culture media. FIG. 54 shows thesynthesis of a series of zwitterionic buffers derived from asparticacid. These compounds are expected to be very useful in electrophoresisgels as they have a unique charge density and size profile. The sultainederivatives in FIG. 55 and FIG. 56 are expected to find great utility incell culture media and in purification due to their zwitterionic natureand pKa range. The zwitterionic buffers of FIG. 57 are expected to beprimarily useful in cell culture media.

As outlined earlier, it is obvious to one skilled in the art that theresulting amines can be reacted further with vinyl acids,monochloroacetic acid, sodium vinyl sulfonate, or an oxirane sulfonateto further add acidic character to the zwitterionic buffer.

Several descriptions and illustrations have been presented to enhanceunderstanding of the present invention. One skilled in the art will knowthat numerous changes and variations are possible without departing fromthe spirit of the invention. Each of these changes and variations arewithin the scope of the present invention.

1. A biological buffer of the following structure:

Where n is from 2 to 8 and A is chosen from the following: —CH₃,—CH₂CH₃, —OH, —CH₂COOH.
 2. A biological buffer of claim 1 where n=2 andA is —CH₃.
 3. A biological buffer of the following structure:


4. A biological buffer of the following structure:


5. A gas scrubbing or buffering amine of the following structure:


6. A gas scrubbing or buffering amine of the following structure:

Where A is chosen from —CH₃, —CH₂CH₃, —CH₂OH, or —H.
 7. A biologicalbuffer of the following structure:

Where A is chosen from the group —OH, —CH₃, or —CH₂CH₃, and M⁺ is acation.
 8. A biological buffer of the following structure:

Where A is chosen from the group —H, —OH, —CH₃, or —CH₂CH₃ and M⁺ is acation.
 9. A biological buffer of the following structure:

Where n and m are integers independently chosen from 1-3.
 10. Abiological buffer of the following structure:

where n is an integer from 1 to
 3. 11. A biological buffer of claim 10where n=1.
 12. A biological buffer of claim 10 where n=2.